Sprocket CHANGE ???

[skeeter]

My son has a 2001 Honda TRX90 and we are ready to move a little bit further, just wondering what size sprocket change would be best ??? I have cut the pink wire, slip-on FMF pipe, and ITP wheels and tires. Just looking for some help for racing ???

[blazen582]

What is the deal with cutting the pink wire? My son has a 04 TRX 90, and I am serching for some mods to do for him to get involved in dirt drags.

[3-D Racing Dad]

The pink wire eliminates the 4th gear rev limiter, as far as the sprocket change it all depends on what you want to do with it. If you want more lower end you need to go up in size on the rear, if you want to get more top end you need to go down in size on the rear, if you want a bigger jump either way you go up 1 or down 1 tooth size in the front sproket depending on what you want to do. If you divide the rear sprocket teeth by the front sproket teeth that will give you the gear ratio.

[FASTDAD-77]

I'm sure everyone here has a little different gearing but I use 15 front-48 rear with 16 inch tires and 14 front-48 rear for 18 inch tires on my race engine but stock I went with 13 front-48 rear. My kid weighes about 65 with his boots on and gearing can change with where he races, what he weighes and definently with what motor work has been done. If anybody else has something better, I would take any suggestions also

[blazen582]

Thanks for the info on the pink wire I will have to check that out.. I was planning on the gear change, exhaust, and a rev box. But I was looking around at some of the stroker kits, or top end upgrades. I want to get the most bang for my buck! But I am by far not wanting to spend thousands! I would like to stay under 2,000.00. I am trying to get my son into some local dirt drags. He weighs about 65 pounds. I have found alot of places that sell the engine kits, but noone who installs them.. I would like to send off the complete motor and have the work done!

[ROBBSRACING]

We can do that !

[FASTDAD-77]

Does anybody know how to figure tire size into the gearing ratio?